The present invention relates generally to dental office equipment of the type commonly used in dentists' offices for routine patient procedures. More particularly, the present invention relates to a novel apparatus for supporting and controlling delivery of fluids, such as air and water, to a dental handpiece, such as a dentist's drill.
Currently, conventional equipment used by practicing dentists typically comprises a variety of hand-held power-operated tools for performing differing dental procedures, one of the most common and familiar of which, by way of example, is a drill used for removing decayed portions of teeth preparatory to filling with a protective material. Typically, such drills and like dental handpieces are driven by compressed air and it is also commonplace for a cooling fluid, usually air, water or a mixture thereof, to be delivered to the handpiece for emission into the drilling or other work area for cooling purposes.
To facilitate convenient usage of such handpieces by dentists, a conduit system is provided in the dentist's office to provide a ready source of compressed air and pressurized water and is equipped with an associated valving system, normally actuated and deactuated through a foot-operated device, to enable the dentist to selectively control fluid delivery to the dental handpieces being utilized.
In the past, such valving systems have been relatively complicated and, in turn, costly, not only to manufacture but also to service when in need of repair. Accordingly, a need has existed for a simplified and less costly form of valve system for controlling delivery of operating fluids to dental handpieces.
U.S. Pat. No. 4,375,963, represents a relatively recent development addressing this problem and need. Basically, this patent discloses a control unit for dental handpieces wherein a handpiece holder is carried on a pivoting support arm mounted to a suitable frame member. A resiliently flexible tube is attached to the handpiece and extends therefrom through the frame member in a configuration tending to urge the support arm into an upwardly pivoted position when the handpiece is removed from the holder. An actuator is mounted in a stationary position on the frame member adjacent the holder for engagement by the handpiece when inserted into the holder to cause the support arm to pivot into a downward position. In such position, opposing pinch members mounted on the frame member and the support arm are moved into sufficiently close proximity to one another to physically clamp the flexible tube between the pinch members and thereby close the tube to prevent further fluid flow to the handpiece. Upon subsequent removal of the handpiece from the holder, the natural resiliency of the tube urges the support arm into its upward disposition, thereby separating the pinch members to allow fluid flow through the tube.